JP2019079613A - Power storage module - Google Patents

Abstract

Provided is an electricity storage module capable of suppressing deformation of a terminal electrode even when an internal pressure rises. In an electricity storage module (4), a negative terminal electrode (18) and a positive electrode terminal having an electrode plate (15) on which a positive electrode (16) and a negative electrode (17) are formed on a stack end of an electrode stack (11) inward in the stack direction. The electrode 19 is arranged, the sealing body 12 is coupled to the edge portion 15c of the electrode plate 15 in the negative electrode termination electrode 18 and the positive electrode termination electrode 19, and the lamination direction of the electrode laminated body 11 is determined from the edge of the electrode plate 15. The resin portions 32 and 42 having the overhanging portions 32b and 42b projecting in the direction orthogonal to the direction are included. In the resin portions 32 and 42, the resin portions 32 and 42 are formed in regions corresponding to the overhanging portions 32b and 42b. Resin films 33 and 43 made of a resin material having a higher tensile strength than the resin material. [Selection diagram] Fig. 3

Description

  The present invention relates to a storage module.

  As a conventional storage module, there is known a so-called bipolar storage module including a bipolar electrode in which a positive electrode is formed on one surface of an electrode plate and a negative electrode is formed on the other surface (see Patent Document 1). The storage module includes an electrode stack formed by stacking a plurality of bipolar electrodes via a separator. The sealing body which seals between the bipolar electrodes which adjoin in the lamination direction is provided in the side of an electrode laminated body. An electrolytic solution is accommodated in an internal space formed between the sealing body and the bipolar electrode.

JP, 2011-204386, A

  In the storage module described above, the internal pressure of the internal space between the bipolar electrodes may increase depending on the use conditions and the like. Even when the internal pressure is increased, the load due to the internal pressure of the internal space adjacent in the stacking direction is canceled in the intermediate layer of the electrode stack. In addition, since the internal space itself is a slight space, deformation of the electrode is relatively difficult to occur. On the other hand, unlike the middle layer, the load due to the internal pressure of the inner space is not canceled at the electrode located at the lamination end of the electrode lamination (hereinafter referred to as the terminal electrode). For this reason, it is conceivable that the terminal electrode deforms to the outside in the stacking direction when the internal pressure rises.

  When the end electrode is deformed, the seal is excessively stressed, and the seal may be broken or a gap may be generated between the seal and the end electrode. The breakage of the sealing body and the formation of the gap between the sealing body and the terminal electrode may cause leakage of the electrolyte to the outside of the electrode stack. Therefore, a technique for suppressing the deformation of the terminal electrode even when the internal pressure rises is desired.

  The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an electric storage module capable of suppressing deformation of the terminal electrode even when the internal pressure rises.

  An electricity storage module according to one aspect of the present invention includes an electrode stack body in which a plurality of bipolar electrodes are stacked via a separator, and a seal that is provided on the side surface of the electrode stack body and seals between bipolar electrodes adjacent in the stacking direction. A termination electrode is disposed which has an electrode plate having a stop, and at the lamination end of the electrode laminate, one of the positive electrode and the negative electrode is formed on the surface facing inward in the lamination direction. The resin portion includes a resin portion coupled to an edge portion of the electrode plate in the terminal electrode and having an overhang portion extending from the edge of the electrode plate in a direction orthogonal to the laminating direction of the electrode laminate. In the corresponding region, a resin film made of a resin material having a tensile strength higher than that of the resin material constituting the resin portion is disposed.

  In this storage module, a resin film is disposed in a region corresponding to the overhang portion in the resin portion. The resin material constituting the resin film has higher tensile strength than the resin material constituting the resin part. Therefore, since the resin portion is reinforced by the resin film, it is possible to suppress deformation of the terminal electrode to which the resin portion is bonded even when the internal pressure of the storage module is increased. By suppressing the deformation of the terminal electrode, it is possible to suppress the breakage of the resin part and the formation of the gap between the resin part and the terminal electrode, and the leakage of the electrolytic solution to the outside of the electrode laminate can be prevented.

  The resin film may be disposed over a region where the resin portion and the electrode plate overlap. Thereby, the resin part can be further sufficiently reinforced by the resin film.

  The resin film may be disposed on the surface of the resin portion facing the outside in the stacking direction. In this case, it is possible to select a material having no resistance to the electrolytic solution as a constituent material of the resin film.

  The resin film may be disposed on the surface of the resin portion facing inward in the stacking direction. Even in such a configuration, the resin part can be firmly reinforced by the resin film.

  A resin portion may be bonded to a terminal electrode having an electrode plate on which a positive electrode is formed, via a resin film. In this case, in the terminal electrode on the positive electrode side, the formation of the gap between the resin portion and the terminal electrode can be suitably suppressed.

  The bonding surface of the electrode plate to the resin portion may be a roughened plating surface. By forming the roughened plating surface, the bonding strength between the electrode plate and the resin portion can be improved. Therefore, the formation of the gap between the resin portion and the terminal electrode can be further suitably suppressed.

  According to the present invention, deformation of the terminal electrode can be suppressed even when the internal pressure rises.

It is a schematic sectional drawing which shows one Embodiment of an electrical storage apparatus. It is a schematic sectional drawing which shows one Embodiment of an electrical storage module. It is a principal part expanded sectional view which shows an example of a structure of the termination | terminus electrode vicinity of the negative electrode side of the electrical storage module shown in FIG. It is a principal part expanded sectional view which shows an example of a structure of the termination | terminus electrode vicinity of the positive electrode side of the electrical storage module shown in FIG. It is a principal part expanded sectional view showing a situation of a termination electrode at the side of a negative electrode at the time of internal pressure rise in a storage module concerning a comparative example. It is a principal part expanded sectional view which shows the mode of the termination electrode of the positive electrode side at the time of internal pressure rise in the electrical storage module which concerns on a comparative example. It is a principal part expanded sectional view showing the modification of the composition of the termination electrode neighborhood by the side of the negative electrode. It is a principal part expanded sectional view showing other modifications of composition near the termination electrode by the side of negative electrode. It is a principal part expanded sectional view showing a modification of composition near the termination electrode by the side of positive electrode. It is a principal part expanded sectional view showing other modifications of composition near the termination electrode by the side of positive electrode.

Hereinafter, preferred embodiments of the storage module will be described in detail with reference to the drawings.
[Configuration of power storage device]

  FIG. 1 is a schematic cross-sectional view showing an embodiment of a power storage device. The storage device 1 shown in the figure is used, for example, as a battery of various vehicles such as a forklift, a hybrid car, and an electric car. The storage device 1 is configured to include a storage module stack 2 formed by stacking a plurality of storage modules 4 and a restraint member 3 that applies a restraint load to the storage module stack 2 in the stacking direction.

  The storage module laminate 2 is configured of a plurality (three in the present embodiment) of storage modules 4 and a plurality (four in the present embodiment) of conductive plates 5. The storage module 4 is, for example, a bipolar battery provided with a bipolar electrode 14 described later, and has a rectangular shape when viewed from the stacking direction. The storage module 4 is, for example, a nickel-hydrogen secondary battery, a secondary battery such as a lithium ion secondary battery, or an electric double layer capacitor. The following description exemplifies a nickel-hydrogen secondary battery.

  In the storage module stack 2, the storage modules 4, 4 adjacent to each other in the stacking direction are electrically connected via the conductive plate 5. The conductive plates 5 are respectively disposed between the storage modules 4 4 adjacent to each other in the stacking direction and on the outer side of the storage module 4 located at the stacking end. The positive electrode terminal 6 is connected to one of the conductive plates 5 disposed on the outer side of the storage module 4 located at the lamination end. The negative electrode terminal 7 is connected to the other conductive plate 5 disposed outside the power storage module 4 located at the stacking end. The positive electrode terminal 6 and the negative electrode terminal 7 are drawn out, for example, from the edge of the conductive plate 5 in the direction crossing the stacking direction. Charging and discharging of the power storage device 1 are performed by the positive electrode terminal 6 and the negative electrode terminal 7.

  Inside each conductive plate 5, a plurality of flow paths 5a for circulating a refrigerant such as air are provided. The respective flow paths 5a extend parallel to each other in a direction orthogonal to, for example, the stacking direction and the drawing direction of the positive electrode terminal 6 and the negative electrode terminal 7. In addition to the function as a connecting member for electrically connecting the storage modules 4 and 4 to each other, the conductive plate 5 dissipates heat generated by the storage module 4 by circulating the refrigerant through the flow paths 5a. It also has the function of In the example of FIG. 1, the area of the conductive plate 5 viewed from the stacking direction is smaller than the area of the storage module 4, but from the viewpoint of improvement of heat dissipation, the area of the conductive plate 5 is the storage module The area of 4 may be the same, or the area of the storage module 4 may be larger.

  The restraint member 3 includes a pair of end plates 8 and 8 sandwiching the storage module stack 2 in the stacking direction, and a fastening bolt 9 and a nut 10 for fastening the end plates 8 and 8 to each other. The end plate 8 is a rectangular metal plate having an area slightly larger than the areas of the storage module 4 and the conductive plate 5 as viewed in the stacking direction. A film F having electrical insulation is provided on the inner side surface (the surface on the side of the storage module stack 2) of the end plate 8, and the end plate 8 and the conductive plate 5 are electrically insulated. .

At the edge of the end plate 8, an insertion hole 8 a is provided at a position outside the power storage module laminate 2. The fastening bolt 9 is passed from the insertion hole 8a of one end plate 8 toward the insertion hole 8a of the other end plate 8, and the tip portion of the fastening bolt 9 protrudes from the insertion hole 8a of the other end plate 8 , The nut 10 is screwed. As a result, the storage module 4 and the conductive plate 5 are sandwiched by the end plates 8 and 8 to be unitized as the storage module stack 2, and a restraint load is applied to the storage module stack 2 in the stacking direction.
[Configuration of storage module]

  Next, the configuration of the storage module 4 will be described. FIG. 2 is a schematic cross-sectional view showing an embodiment of a storage module. As shown to the same figure, the electrical storage module 4 is equipped with the electrode laminated body 11 and the resin-made sealing body 12 which seals the electrode laminated body 11. As shown in FIG.

  The electrode stack 11 is configured by stacking a plurality of bipolar electrodes 14 via a separator 13. In the present embodiment, the stacking direction of the electrode stack 11 and the stacking direction of the storage module stack 2 coincide with each other. The electrode stack 11 has side surfaces 11 a extending in the stacking direction. The bipolar electrode 14 includes an electrode plate 15, a positive electrode 16 provided on one surface 15 a of the electrode plate 15, and a negative electrode 17 provided on the other surface 15 b of the electrode plate 15. The positive electrode 16 is a positive electrode active material layer formed by coating a positive electrode active material. The negative electrode 17 is a negative electrode active material layer formed by coating a negative electrode active material. In the electrode stack 11, the positive electrode 16 of one bipolar electrode 14 faces the negative electrode 17 of one bipolar electrode 14 adjacent in the stacking direction across the separator 13. In the electrode stack 11, the negative electrode 17 of one bipolar electrode 14 faces the positive electrode 16 of the other bipolar electrode 14 adjacent in the stacking direction across the separator 13.

  In the electrode stack 11, the negative electrode termination electrode 18 is disposed at one end in the stacking direction. Moreover, the positive electrode terminal electrode 19 is arrange | positioned at the other end of the lamination direction. The negative electrode terminal electrode 18 includes an electrode plate 15 and a negative electrode 17 provided on the other surface 15 b of the electrode plate 15. The negative electrode 17 of the negative electrode terminal electrode 18 faces the positive electrode 16 of the bipolar electrode 14 at one end in the stacking direction via the separator 13. One conductive plate 5 adjacent to the storage module 4 is in contact with one surface 15 a of the electrode plate 15 of the negative electrode terminal electrode 18. The positive electrode terminal electrode 19 includes an electrode plate 15 and a positive electrode 16 provided on one surface 15 a of the electrode plate 15. The other conductive plate 5 adjacent to the storage module 4 is in contact with the other surface 15 b of the electrode plate 15 of the positive electrode terminal electrode 19. The positive electrode 16 of the positive electrode terminal electrode 19 is opposed to the negative electrode 17 of the bipolar electrode 14 at the other end in the stacking direction via the separator 13.

  The electrode plate 15 is made of, for example, a metal foil made of nickel or a nickel-plated steel plate, and has a rectangular shape. The edge 15 c of the electrode plate 15 is an uncoated region on which the positive electrode active material and the negative electrode active material are not applied. As a positive electrode active material which comprises the positive electrode 16, nickel hydroxide is mentioned, for example. As a negative electrode active material which comprises the negative electrode 17, a hydrogen storage alloy is mentioned, for example. In the present embodiment, the formation region of the negative electrode 17 on the other surface 15 b of the electrode plate 15 is one size larger than the formation region of the positive electrode 16 on the one surface 15 a of the electrode plate 15.

  The separator 13 is formed in, for example, a sheet shape. Examples of the separator 13 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or non-woven fabrics made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like. The separator 13 may be reinforced with a vinylidene fluoride resin compound. The separator 13 is not limited to a sheet but may be a bag.

  The sealing body 12 is formed in, for example, a rectangular cylindrical shape by an insulating resin. The sealing body 12 is configured to hold the edge 15 c of the electrode plate 15 at the side surface 11 a of the electrode stack 11 extending in the stacking direction and to surround the side surface 11 a. The sealing body 12 is a primary sealing body 21 provided along the edge 15 c of the electrode plate 15 of each bipolar electrode 14 and two provided so as to surround the entire primary sealing body 21 from the outside. It is constituted by the next sealing body 22. The primary sealing body 21 is formed, for example, by injection molding of a resin, and is continuously provided over all the sides of the electrode plate 15 at an edge portion 15c (uncoated region) on one surface 15a side of the electrode plate 15 There is. The primary sealing body 21 is firmly coupled to the edge 15 c by welding using, for example, ultrasonic waves or heat.

  The primary sealing body 21 not only seals between the bipolar electrodes 14 and 14 adjacent in the stacking direction, but also functions as a spacer between the electrode plates 15 and 15 of the bipolar electrodes 14 and 14 adjacent in the stacking direction. An internal space V defined by the distance between the primary sealing bodies 21 and 21 in the stacking direction is formed between the electrode plates 15 and 15. In the internal space V, an electrolytic solution E made of an alkaline solution such as a potassium hydroxide aqueous solution is accommodated.

  When bonding the primary sealing body 21 and the electrode plate 15, the bonding surface of the electrode plate 15 to the primary sealing body 21 is a roughened plating surface 23 provided with a plurality of fine projections. In the present embodiment, the entire surface of one surface 15 a of the electrode plate 15 provided with the positive electrode 16 is a roughened plating surface 23. The fine projection is, for example, a projection-like deposited metal (including an applied substance) formed by electrolytic plating on the electrode plate 15. On the roughened plating surface 23, the resin material constituting the primary sealing body 21 enters into the gaps between the fine projections to produce an anchor effect, and the bonding strength between the electrode plate 15 and the primary sealing body 21 and the liquid Denseness can be improved.

The secondary sealing body 22 is formed, for example, by injection molding of a resin, and extends over the entire length in the stacking direction of the electrode stack 11. The secondary sealing body 22 is welded to the outer surface of the primary sealing body 21 by, for example, heat at the time of injection molding. In the sealing body 12, the electrolytic solution E accommodated in the internal space V can pass between the primary sealing bodies 21 and 21 adjacent in the stacking direction, but the electrolytic solution E between the primary sealing body 21 and the secondary sealing body 22 It is sealed by the welding part.
[Detailed Configuration of Primary Sealed Body]

  Next, the above-described primary sealing body 21 will be described in more detail. FIG. 3 is an enlarged sectional view of an essential part showing an example of the configuration in the vicinity of the terminal electrode on the negative electrode side of the storage module. Moreover, FIG. 4 is a principal part expanded sectional view which shows an example of a structure of the termination | terminus electrode vicinity of the positive electrode side of an electrical storage module.

  The primary sealing body 21 coupled to the bipolar electrode 14 which is an intermediate layer of the electrode stack 11 is, as shown in FIGS. 3 and 4, an overlapping portion 31a overlapping the edge 15c of the one surface 15a of the electrode plate 15. And a resin portion 31 having a protruding portion 31 b protruding to the outside of the edge of the electrode plate 15. The overlapping portion 31 a constitutes the inner peripheral side of the primary sealing body 21. The overlapping portion 31 a is provided with a step portion 31 c in which the edge of the separator 13 is disposed. The height of the step portion 31c is, for example, about the same as the thickness of the separator 13, and the separator 13 and the overhang portion 31b are substantially flush. The separator 13 and the step portion 31c are coupled to each other, for example, by welding. The overhanging portion 31 b is located on the outer peripheral side of the primary sealing body 21, and overhangs in a direction (in-plane direction of the electrode plate 15) orthogonal to the stacking direction of the electrode stack 11 from the edge of the electrode plate 15. A part of the outer edge portion of the overhang portion 31 b is buried in the secondary sealing body 22.

  As shown in FIG. 3, the primary sealing body 21 coupled to the negative electrode terminal electrode 18 disposed at one of the laminated ends of the electrode laminate 11 overlaps the edge 15 c of the one surface 15 a of the electrode plate 15. It has a resin portion 32 having a portion 32 a and an overhanging portion 32 b projecting outward beyond the edge of the electrode plate 15. At the boundary between the overlapping portion 32a and the overhanging portion 32b, a step portion 32c in which the edge 15c of the electrode plate 15 is disposed is provided. The stepped portion 32 c is formed on the surface of the resin portion 32 facing inward in the stacking direction. The height of the step portion 32c is, for example, about the same as the thickness of the electrode plate 15, and the electrode plate 15 and the overhang portion 32b are substantially flush. The overhanging portion 32 b is located on the outer peripheral side of the primary sealing body 21 and overhangs from the edge of the electrode plate 15 in the direction perpendicular to the stacking direction of the electrode stack 11 (in-plane direction of the electrode plate 15). A part of the outer edge of the overhang portion 32 b is buried in the secondary sealing body 22.

  In the resin portion 32, a resin film 33 made of a resin material having a tensile strength higher than that of the resin material constituting the resin portion 32 is disposed in a region corresponding to the overhang portion 32b. In the present embodiment, the resin film 33 is disposed on the surface of the resin portion 32 facing the outside in the stacking direction. Further, in the present embodiment, the resin film 33 is bonded to the resin portion 32 not only in the region corresponding to the overhang portion 32 b but also the entire region corresponding to the overhang portion 32 b and the region corresponding to the overlap portion 32 a There is. A part of the outer edge portion of the resin film 33 is buried in the secondary sealing body 22 together with the overhang portion 32 b. The thickness of the resin film 33 is not particularly limited as long as the secondary sealing body 22 does not protrude in the stacking direction more than the conductive plate 5 in contact with the negative electrode terminal electrode 18. The thickness of the resin film 33 may be smaller than, for example, the thickness of the overhanging portion 32 b of the resin portion 32, and may be smaller than the thickness of the overlapping portion 32 a.

  As shown in FIG. 4, the primary sealing body 21 coupled to the positive electrode terminal electrode 19 disposed at the other lamination end of the electrode laminated body 11 overlaps the edge 15c of the one surface 15a of the electrode plate 15 It has a resin portion 42 having a portion 42 a and an overhang portion 42 b projecting outward beyond the edge of the electrode plate 15. The overlapping portion 42 a is provided with a step portion 42 c in which the edge of the separator 13 is disposed. The height of the step portion 42c is, for example, about the same as the thickness of the separator 13, and the separator 13 and the overhang portion 42b are substantially flush. The separator 13 and the step portion 42c are coupled to each other, for example, by welding. The overhanging portion 42 b is located on the outer peripheral side of the primary sealing body 21, and overhangs from the edge of the electrode plate 15 in the direction orthogonal to the stacking direction of the electrode stack 11 (in-plane direction of the electrode plate 15). A part of the outer edge of the overhang portion 42 b is buried in the secondary sealing body 22.

  In the resin portion 42, the resin film 43 made of a resin material having a tensile strength higher than that of the resin material constituting the resin portion 41 is disposed in the region corresponding to the overhang portion 42b. In the present embodiment, the resin film 43 is disposed on the surface of the resin portion 42 facing the outside in the stacking direction. Further, in the present embodiment, the resin film 43 is bonded to the resin portion 42 not only in the region corresponding to the overhang portion 42 b but also over the entire region corresponding to the overhang portion 42 b and the region corresponding to the overlapping portion 42 a There is. A part of the outer edge portion of the resin film 43 is buried in the secondary sealing body 22 together with the overhang portion 42 b. The thickness of the resin film 43 is not particularly limited as long as the secondary sealing body 22 does not protrude in the stacking direction relative to the conductive plate 5 in contact with the positive electrode terminal electrode 19. The thickness of the resin film 43 may be, for example, about the same as the thickness of the overhanging portion 42b of the resin portion 42, or may be smaller than the thickness of the overhanging portion 42b.

  In the resin film 43, a step 43a where the edge 15c of the electrode plate 15 is disposed is provided at a position corresponding to the boundary between the overlapping portion 42a and the overhang portion 42b. The step 43 a is formed on the surface of the resin film 43 facing the outside in the stacking direction. The resin portion 42 is coupled to the edge portion 15 c of the electrode plate 15 of the positive electrode terminal electrode 19 through the resin film 43 by using the step portion 43 a. The height of the step portion 43a is, for example, about the same as the thickness of the electrode plate 15, and the electrode plate 15 and the resin film 43 are substantially flush.

Examples of the resin material constituting the resin portions 31, 32, 42 of the primary sealing body 21 include acid-modified polypropylene, modified polyphenylene ether, polypropylene, thermoplastic elastomer in which a rubber component and polypropylene are mixed, and the like. Moreover, as a material which comprises the secondary sealing body 22, denatured polyphenylene ether is mentioned, for example. Examples of resin materials constituting the resin films 33 and 43 include acid-modified polypropylene, modified polyphenylene ether, polypropylene, polyolefin, and polyethylene terephthalate.
[Function effect]

  FIG. 5 is an enlarged sectional view of an essential part showing a state of the terminal electrode on the negative electrode side when the internal pressure rises in the storage module according to the comparative example. Moreover, FIG. 6 is a principal part expanded sectional view which shows the mode of the termination electrode of the positive electrode side at the time of internal pressure raise in the electrical storage module which concerns on a comparative example. Unlike the storage module 4 according to the above embodiment, in the storage module 100 according to the comparative example shown in FIGS. 5 and 6, a resin film is used as the primary sealing body 121 coupled to the negative electrode termination electrode 118 and the positive electrode termination electrode 119. 33, 43 are not provided. In the storage module 100, when the internal pressure of the internal space V between the bipolar electrodes 114, 114 rises due to use conditions etc., the load due to the internal pressure of the internal space V adjacent in the stacking direction is canceled in the intermediate layer of the electrode stack 111. Ru. Further, since the internal space V itself is a slight space, deformation of the bipolar electrode 114 is relatively difficult to occur.

  On the other hand, in the negative electrode termination electrode 118 and the positive electrode termination electrode 119 located at the lamination end of the electrode stack 111, unlike the intermediate layer, the load due to the internal pressure of the internal space V is not canceled. Therefore, as shown in FIG. 5 and FIG. 6, it can be considered that the negative electrode terminal electrode 118 and the positive electrode terminal electrode 119 deform to the outside in the stacking direction when the internal pressure rises. Such deformation is likely to occur particularly in the portion where the restraining force between the conductive plate and the secondary sealing body 122 is not applied. When deformation occurs in the negative electrode termination electrode 118 and the positive electrode termination electrode 119, an excessive stress is applied to the primary sealing body 121, and the primary sealing body 121 is broken or the primary sealing body 121, the negative electrode termination electrode 118, and the positive electrode termination A gap may be generated between the electrode 119 and the electrode 119. The breakage of the primary sealing body 121 and the formation of a gap between the primary sealing body 121 and the negative electrode termination electrode 118 and the positive electrode termination electrode 119 may cause leakage of the electrolyte solution E to the outside of the electrode stack 111.

  On the other hand, in the storage module 4, the resin film 33 is disposed in the region corresponding to the overhanging portion 32 b in the resin portion 32 of the primary sealing body 21 coupled to the negative electrode terminal electrode 18. Similarly, in the resin portion 42 of the primary sealing body 21 coupled to the positive electrode terminal electrode 19, the resin film 43 is disposed in a region corresponding to the overhang portion 42b. The resin materials constituting the resin films 33 and 43 have higher tensile strength than the resin materials constituting the resin portions 32 and 42. Therefore, since the resin portions 32 and 42 are reinforced by the resin films 33 and 43, the negative electrode terminal electrode 18 and the resin portion 42 to which the resin portion 32 is bonded even when the internal pressure of the storage module 4 increases. It is possible to suppress the deformation of the positive electrode terminal electrode 19 that is coupled.

  By suppressing deformation of the negative electrode termination electrode 18 and the positive electrode termination electrode 19, breakage of the resin portions 32, 42, formation of a gap between the resin portion 32 and the negative electrode termination electrode 18, resin portion 42 and the positive electrode termination electrode 19 The formation of a gap between them can be suppressed, and the leakage of the electrolytic solution E to the outside of the electrode stack 11 can be prevented. Such a configuration is particularly significant when it is difficult to obtain the tensile strength of the primary sealing body 21 itself from the viewpoint of selecting a resin material having resistance (here, alkali resistance) to the electrolytic solution E as the primary sealing body 21. It becomes a thing.

  In addition, in the storage module 4, the resin film 33 is disposed in the region corresponding to the overlapping portion 32 a overlapping the electrode plate 15 in addition to the region corresponding to the overhang portion 32 b. Similarly, in the storage module 4, the resin film 43 is disposed in the region corresponding to the overlapping portion 42 a overlapping the electrode plate 15 in addition to the region corresponding to the overhang portion 42 b. As a result, the resin portions 32 and 42 can be further sufficiently reinforced by the resin films 33 and 43.

  The resin film 33 may not necessarily be disposed over the entire region corresponding to the overlapping portion 32a, and the entire region corresponding to the overhanging portion 32b and a part of the region corresponding to the overlapping portion 32a. It may be arranged across the Similarly, the resin film 43 may not necessarily be disposed over the entire region corresponding to the overlapping portion 42a, and the entire region corresponding to the overhang portion 42b and a part of the region corresponding to the overlapping portion 42a And may be arranged across the

  Further, in the storage module 4, the resin film 33 is disposed on the surface of the resin portion 32 facing the outside in the stacking direction. Similarly, the resin film 43 is disposed on the surface of the resin portion 42 facing the outside in the stacking direction. Thereby, it is possible to select a material having no resistance to the electrolytic solution E as a constituent material of the resin films 33, 43. Therefore, the range of selection of the constituent material is expanded, and a resin material having more sufficient tensile strength can be used as the constituent material of the resin films 33, 43.

  Further, in the storage module 4, the electrode plate 15 of the positive electrode terminal electrode 19 is coupled to the resin portion 42 through the resin film 43. Thereby, in the positive electrode terminal electrode 19, the formation of the gap between the resin portion 42 and the positive electrode terminal electrode 19 can be suitably suppressed.

Furthermore, in the storage module 4, the bonding surface of the electrode plate 15 to the resin portions 32 and 42 is a roughened plating surface 23. The formation of the roughened plating surface 23 improves the bonding strength between the electrode plate 15 and the resin portions 32 and 42. Therefore, the formation of the gap between the resin portion 32 and the negative electrode terminal electrode 18 and the formation of the gap between the resin portion 42 and the positive electrode terminal electrode 19 can be further suitably suppressed.
[Modification]

  The present invention is not limited to the above embodiment. For example, in the embodiment described above, in the resin portion 32 coupled to the electrode plate 15 of the negative electrode termination electrode 18, the resin film 33 is disposed over the entire region corresponding to the overhang portion 32b and the region corresponding to the overlapping portion 32a. For example, as shown in FIG. 7, the resin film 33 may be disposed only in the region corresponding to the overhang portion 32 b in the resin portion 32.

  Also in the resin portion 42 joined to the electrode plate 15 of the positive electrode terminal electrode 19, similarly, for example, as shown in FIG. 8, the resin film 43 is disposed only in the region corresponding to the overhang portion 42 b in the resin portion 42 May be In the example of FIG. 8, the step portion 43 a is not provided in the resin film 43, and the electrode plate 15 and the resin are provided by providing the electrode plate 15 and the resin film 43 of equal thickness in the region corresponding to the overhang portion 42 b. The film 43 is substantially flush with the film 43.

  In the portion coupled to the electrode plate 15, the strength of the resin portions 32, 42 can be relatively easily secured. Therefore, also in the configurations shown in FIGS. 7 and 8, the resin portions 32 and 42 are sufficiently reinforced by the resin films 33 and 43. Therefore, even when the internal pressure of the storage module 4 increases, deformation of the negative electrode terminal electrode 18 to which the resin portion 32 is bonded and the positive electrode terminal electrode 19 to which the resin portion 42 is bonded can be suppressed.

  Further, for example, in the above-described embodiment, the resin film 33 is disposed on the surface facing the outside in the stacking direction in the resin portion 32 coupled to the electrode plate 15 of the negative electrode terminal electrode 18. Alternatively, the resin film 33 may be disposed on the surface of the resin portion 32 facing inward in the stacking direction. In the example of FIG. 9, the resin film 33 is disposed only in the region corresponding to the overhanging portion 32 b so as not to overlap the electrode plate 15. Further, in the example of FIG. 9, the thickness of the overhanging portion 32b of the resin portion 32 is reduced by the thickness of the resin film 33, whereby the electrode plate 15 and the resin film 33 are substantially flush. It has become.

  Also in the resin portion 42 joined to the electrode plate 15 of the positive electrode terminal electrode 19, similarly, for example, as shown in FIG. 10, the resin film 43 may be disposed on the surface facing inward in the stacking direction. In the example of FIG. 10, the positional relationship between the resin portion 42 and the resin film 43 is reversed as compared with the example of FIG. 4, and the resin portion 42 is directly bonded to the edge 15 c of the electrode plate 15. In the resin portion 42, at a position corresponding to the boundary between the overlapping portion 42a and the overhang portion 42b, a step portion 42c in which the edge 15c of the electrode plate 15 is disposed is provided. The step portion 42 c is formed on the surface of the resin portion 42 facing the outside in the stacking direction. The height of the step portion 42c is, for example, about the same as the thickness of the electrode plate 15, and the electrode plate 15 and the resin portion 42 are substantially flush.

  Further, in the example of FIG. 10, the resin film 43 is disposed on the entire area of the region corresponding to the overhang portion 42b and the region corresponding to the overlapping portion 42a on the surface of the resin portion 42 facing inward in the stacking direction. Further, the resin film 43 is provided with a stepped portion 43a in which the edge portion of the separator 13 is disposed substantially flush in the region corresponding to the overlapping portion 42a. The height of the step portion 43a is, for example, about the same as the thickness of the separator 13, and the separator 13 and the resin film 43 are substantially flush.

  When the resin material having resistance to the electrolytic solution E is selected as the resin material constituting the resin films 33 and 43, the resin portions 32 and 42 are firmly fixed by the resin films 33 and 43 even in the configurations shown in FIGS. It can be reinforced. Therefore, even when the internal pressure of the storage module 4 increases, deformation of the negative electrode terminal electrode 18 to which the resin portion 32 is bonded and the positive electrode terminal electrode 19 to which the resin portion 42 is bonded can be suppressed.

  DESCRIPTION OF SYMBOLS 4 ... Storage module, 11 ... Electrode laminated body, 11a ... Side surface, 12 ... Sealed body, 13 ... Separator, 14 ... Bipolar electrode, 15 ... Electrode plate, 15c ... Edge part, 16 ... Positive electrode, 17 ... Negative electrode, 18 ... Negative electrode terminal electrode (terminal electrode), 19: positive electrode terminal electrode (terminal electrode), 23: roughened plated surface, 32, 42: resin portion, 32b, 42b, overhang portion, 33, 43: resin film.

Claims (6)

An electrode stack in which a plurality of bipolar electrodes are stacked via a separator;
A sealing body provided on the side surface of the electrode stack and sealing between the bipolar electrodes adjacent in the stacking direction;
A terminal electrode having an electrode plate in which one of a positive electrode and a negative electrode is formed on the surface facing inward in the stacking direction is disposed at the stacking end of the electrode stack,
The sealing body includes a resin portion coupled to an edge portion of the electrode plate in the terminal electrode and having an overhanging portion extending from the edge of the electrode plate in a direction orthogonal to the stacking direction of the electrode stack. ,
A storage module in which a resin film made of a resin material having a tensile strength higher than that of a resin material constituting the resin portion is disposed in a region corresponding to the overhang portion in the resin portion.   The storage module according to claim 1, wherein the resin film is disposed over a region where the resin portion and the electrode plate overlap.   The power storage module according to claim 1, wherein the resin film is disposed on a surface of the resin portion facing outward in the stacking direction.   The storage module according to claim 1, wherein the resin film is disposed on a surface of the resin portion facing inward in the stacking direction.   The power storage module according to any one of claims 1 to 3, wherein the resin portion is coupled to a terminal electrode having an electrode plate on which the positive electrode is formed via the resin film.   The storage module according to any one of claims 1 to 5, wherein a bonding surface of the electrode plate to the resin portion is a roughened plating surface.

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